#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkCommand.h>
#include <vtkLineRepresentation.h>
#include <vtkLineWidget2.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>

namespace {
// This does the actual work.
// Callback for the interaction
    class vtkLineCallback : public vtkCommand {
    public:
        static vtkLineCallback *New() {
            return new vtkLineCallback;
        }

        virtual void Execute(vtkObject *caller, unsigned long, void *) {

            vtkLineWidget2 *lineWidget = reinterpret_cast<vtkLineWidget2 *>(caller);

            // Get the actual box coordinates of the line
            vtkNew<vtkPolyData> polydata;
            static_cast<vtkLineRepresentation *>(lineWidget->GetRepresentation())
                    ->GetPolyData(polydata);

            // Display one of the points, just so we know it's working
            double p[3], p2[3];
            polydata->GetPoint(0, p);
            polydata->GetPoint(1, p2);
            std::cout << "P1: " << p[0] << " " << p[1] << " " << p[2] << " P2: " << p2[0] << " " << p2[1] << " " << p2[2]  <<std::endl;
        }

        vtkLineCallback() {
        }
    };
} // namespace

int main(int, char *[]) {
    vtkNew<vtkNamedColors> colors;

    vtkNew<vtkSphereSource> sphereSource;
    sphereSource->Update();

    // Create a mapper and actor
    vtkNew<vtkPolyDataMapper> mapper;
    mapper->SetInputConnection(sphereSource->GetOutputPort());
    vtkNew<vtkActor> actor;
    actor->SetMapper(mapper);
    actor->GetProperty()->SetColor(colors->GetColor3d("MistyRose").GetData());

    // A renderer and render window
    vtkNew<vtkRenderer> renderer;
    vtkNew<vtkRenderWindow> renderWindow;
    renderWindow->AddRenderer(renderer);
    renderWindow->SetWindowName("LineWidget2");

    renderer->AddActor(actor);
    renderer->SetBackground(colors->GetColor3d("MidnightBlue").GetData());

    // An interactor
    vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
    renderWindowInteractor->SetRenderWindow(renderWindow);

    vtkNew<vtkLineWidget2> lineWidget;
    lineWidget->SetInteractor(renderWindowInteractor);
    lineWidget->CreateDefaultRepresentation();

    // You could do this if you want to set properties at this point:
    // vtkNew<vtkLineRepresentation> lineRepresentation;
    // lineWidget->SetRepresentation(lineRepresentation);

    vtkNew<vtkLineCallback> lineCallback;

    lineWidget->AddObserver(vtkCommand::InteractionEvent, lineCallback);

    // Render
    renderWindow->Render();

    renderWindowInteractor->Initialize();
    renderWindow->Render();
    lineWidget->On();

    // Begin mouse interaction
    renderWindowInteractor->Start();

    return EXIT_SUCCESS;
}
